NRCS Range Inventory
Scott Woodall, NRCS, completed a range inventory in Fall 2005. Information on stocking rates and pasture production has been provided. A grazing database was established in Spring 2006 to compare these values to actual use.
Forage Plots
In conjunction with Joe Brummer (pictured), forage plots were established in 2002.
Improved Pasture
Results from a 5 year study where beef grazed Russian Wildrye,
Intermediate Wheatgrass and these two species plus alfalfa show
that beef produced per acre is determined not only for forage
yield, but also by quality of forage. The addition of alfalfa
to pastures increased beef produced per acre 53% and 37% for
Intermediate Wheatgrass and Russian Wildrye mixtures, respectively.
Grazing studies on native range have shown the approximate
amount of beef produced per acre for four different management
alternatives: continuing grazing, 20 lbs.; rotational grazing,
30 lbs.; control oak brush and rotational grazing, 50 lbs.; remove
oak brush and reseed with grass legume mixture, 150 lbs.
Grazing Intensity Study
An eight-year study with yearling cattle grazing on native
oak brush range at four levels of intensity was begun in 1977
to determine the proper stocking rate for a five-month grazing
season. Optimum seasonal stocking rate was determined to be in
the moderate range of six to eight acres per yearling. The relative
proportions of grasses, forbs and shrubs in the diet remained
the same throughout the grazing season in the two lowest stocking
rates. Late in the grazing season, shrub species were selected
with increasing frequency in the two more heavily stocked pastures.
This reduced the quality of the diet and digestibility, and lowered
individual animal gains. Gain per animal favored the light grazed
pastures and gain per acre favored the heavy use pastures. The
moderate level of grazing proved to be most beneficial for producing
beef and maintaining plant vigor and range condition.
Forage Intake of Horses and Cattle
A 1980-81 study evaluating forage intake of horses and cattle
showed mares consumed 20% more forage than cows of approximately
the same weight. Lactating mares and cows consumed 20 and 16%
more forage dry matter that non-lactating animals. Mares grazed
significantly longer than cows (18 hours vs. 11 hours per day).
Diets were similar for the two specie with cattle consuming 7.7%
forbs and browse compared with only 1.4% for horses. Dry matter
digestibility was 10% greater for cows than for mares. Horses
proved to be capable of clipping grass shorter than cattle, which
could be detrimental to the range under heavy use.
Oak Brush Control
More than one million acres of Colorado rangeland is infected
with oak brush. The application of proper brush control and management
practices could ave a tremendous economic impact on the areas
involved. Numerous chemicals and combinations of chemicals have
been used with limited success to control
Gambel Oak. Those which show the most promise have been placed
on the restricted use list because residues could have a detrimental
effect on the environment.
Mechanical treatment such as roller chopping will give temporary
improved forage yields for cattle. Sprouting will occur following
mechanical application for eliminating mature oak brush. Within
a few years the sprouts can present a more serious problem than
the original stand of mature oak.
Goats have been used effectively to control the new growth
of oak brush by keeping the sprouts defoliated. A field, mechanically
treated in 1964, was grazed by goats five consecutive years beginning
in 1968. Only and occasional small sprout could be found on the
treated area in 1987. A 400 acre pasture chained in 1973 and
1976 was grazed by 1000 Angora goats during 1983 to 1985. Approximately
50% of the sprouts were killed on the grazed area. Cattle numbers
were decreased about 10% during the three-year period goats were
in the pasture. Diet studies have shown goats prefer leaves and
new growth of the oak brush over grass. As long as oak sprouts
were plentiful the goats diet will exceed 90% oak leaves and
sprouts.
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